Charging an electric vehicle: The battery goes through these 5 charging phases

January 14, 2025

Charging an electric vehicle: The battery goes through these 5 charging phases


Fast charging your electric vehicle takes place in several phases. While the first four phases mainly serve as preparation, phase 5 is the actual fast-charging phase in which charging is completed.


1) The initial contact: Connecting the electric vehicle to the charging station


The charging process begins with the establishment of a physical connection between the plug of the charging cable and the socket of the charging station.


2) The "small talk": preparation for an intensive exchange of information


The electric vehicle is supplied with low-voltage auxiliary power from the charging station. This activates the vehicle's battery management system (BMS). This then acts as a "moderator" of the charging process and regulates the exchange of information between the vehicle, battery and charging station.


3) The "handshake": exchange of charging-related parameters


With the help of the BMS, information on charging-related parameters (e.g. vehicle power, battery type, battery capacity, SOC value, charging output power) is now exchanged between the vehicle battery and the charging station.


4) The adjustment: configuration of the charging parameters


An individual charging concept is now configured on the basis of the previously exchanged data, i.e. the charging requirements and capacity of the vehicle and the maximum output power of the charging station are matched. This is to ensure that the subsequent charging process runs as smoothly as possible.


5) Fast charging: Efficient fulfillment of the charging needs of the e-vehicle by the charging station


Only now does the actual fast charging process begin. The signal for this comes from the BMS, which sends the vehicle's individual charging current requirements to the charging station, which adjusts its output voltage and current in real time to the vehicle's charging requirements in order to charge it as efficiently as possible. The charging process is monitored by both the BMS and the charging station to ensure charging safety.